The saga over the ChevronWP7 tool for allowing apps to side-load on Windows Phone 7 continues. If you recall, users of this tool were running into potential remote re-locks of their Windows Phone 7 by Microsoft. It turns out that Microsoft is not remotely re-locking devices, but rather, a built-in security feature of Windows Phone 7 is being activated that checks that the phone is legitimately unlocked. Here’s a quote from the ChevronWP7 blog:

In our preliminary discussions with Microsoft, we were surprised to hear that after a short amount of time  approximately two weeks  phones unlocked via ChevronWP7 would revert back to their original locked state. We couldn’t verify this claim at the time and didn’t look into it again.

Our bad. Don’t panic, though!

Contrary to circulating reports, Windows Phone 7 devices unlocked via ChevronWP7 are not being targeted by Microsoft. Instead, the phone is reverting back as a result of a periodic check. Simply put, the phone rings Microsoft and asks “Hey, am I supposed to be unlocked?”. If Microsoft responds with a “No, what are you thinking?”, the phone apologizes and initiates a lock down.

Unfortunately, while in this state, an unsigned application launch results in a misleading (and scary sounding) error message:

“ has been revoked by Microsoft. Please uninstall it.”

So there you have it…Microsoft isn’t reaching their digital hands into your unlocked Windows Phone 7 as we once feared. It’s still unclear whether phones can be unlocked again once the phone gets re-locked.